Electrical indicating instrument.



H. L. VAN VALKBNBURG. ELECTRICAL INDIOATING INSTRUMENT.

APPLIOATION FILE-D SEPT. 29, 1906.

Patented June 15,1909.

Tame/Mm: mar mm L.VUMVWWQ ew uiw taxation L. VAN VALKENBURG, OF NORWOOD OHIO, AS SIGNOR TO ALLIS-CHALMERS COM- RY, A CORPORATION OF NEW JERSEY, AND THE BUL'LOOKELEGTRIG MANUFACTUR- IKG COMPANY, A CORPORATION OF OHIO.

ELECTRICAL IN DIOATING INSTRUMENT.

Qiio, 925,403.

Specification 0! Letters- Patent.

Patented June 15, 1909.

Application 'filed September 29, 1906. Serial No. 836,67 1.

To all whom it may concern:

' Be it known that I, HERMON L. VAN VAL- KENB'URG, citizen of the United States, residing at Norwood, in the county of Hamilton and State of Ohio, have invented certain new and useful In'iprovements in Electrical Indicating Instruments, of which the fol- .lowing is a full, clear, and exact-specification.

mg instruments.

One of the objects of my invention is to provide an instrument having a long scale of widely distributed graduations.

A further object is to provide an instrument which is very sensitive and accurate for all readings throughout the range of the instrument.

1n carrying out my invention 1 provide a movable scale and a movable indicator, the former remaining normally stationary until the indicator moves a predetermined distance, or until the value to be measured ex; ceeds a predetermined amount.

More specifically considered, my invention consists in an electrical i'ncasuring instrument having a movable indicator, and a movable scale, and an actuating device for each, the parts'bcing so arranged and constructed that when the valueto be measured is small,'the indicator moves and the scale remains stationary, but when the value to be measured reaches a certain predetermined amount, or when the indicator has moved a predetern'iined distance, the scale then moves in the opposite direction, the actuating device for the scale being controlled by the indicator. M

' My inventionstill further consists in the combinations and arrangements of parts described in the specification and set forth in the appended claims. t

For a better understanding of my.invention reference is had to the accompanying drawings inw-hich Figure 1 is a sectional plan view of my improved measuring instrument; Fig. 2 is a partial vertical sectional elevation of the same; and Fig. 3 is a diagrannnatic view showingthe circuit connections.

' Referring now to the figures of the draw-' in' 10 re )resent's an insulatin base u 011 7 b which the working parts of the instrument are mounted.

My invention relates to electrical measur- At 11 is a needle or indicator carried by a short spindle 12 pivoted between jewel bearings 13, which may be supported in any desirable manner. in this instance the upper bearing is adjustably mounted in, a bracket 14 secured to the base, and the lower bearing is mounted in the upper end of a plug or spindle 15 adjustably mounted in the base. The needle is provided atone end with" a pointer 16 extending forward to a graduated scale 17, and with a. comparatively short rearwardly extending arm 18.

1n the usual constructions of electrical measuring instruments the needle or indi- 'cator moves relatively to a stationary scale,

or tht. scale moves relatively to 'a stationary indicator. In such instruments therange of movement is generally limited and furthermore the movement of-the movable'element for a certain variation of current or voltage is usually not the same ,at all points in its range of n'iovement. In my improved i11- strument, these and other difiiculties are overcome by arranging both the. indicator and scale for movement, the indicator having only a slight range of movement. and only moving for measuring small values of current or voltage, and the scale being movable in the opposite direction to that in which the indicator moves when the current i or voltage exceeds a definite predetermined amount. I

he indicator may be actuated'by any suitable electromagnetic motive device having .one or more coils connected to the circuit, and sensitive to slight values of current or voltage. In this case the indicator is connected to the movable core 19, of a solenoid-20- having a 'coil 21, the terminals of which are connected .to binding posts 22 and The coil may be a current 0011 or a voltage coil, or' if desired the solenoid may be provided with both a current and a voltage coil so that the pull and movement is proportional to the watts. In the last mentioned case, either the voltage coil or the current coil would generally be wound on the movable core of the solenoid. The

nrovement of the indicator is'limited in QtlCllilllGOlllOH by stationary contact meniloers 2st and 25"arranged a suitable distanceapart and on opposlte sides of the rearwardly ext-ending arm 18. The scale s in this case arranged for pivotal movement 2 I v I 925,403

about the axis of the needle. The scale is provided with a radial arm 26 having an enlarged head or flange 27, and a hub 28 which is mounted on the end of the plug. or spindle 15, being held in place by a nut 29. The accuracy of the instrument is not affected by the friction of the scale on its bearing, in fact the friction is preferably made considerable so that the scale will more" readily remain in its proper position when moved by its actuator.

Any suitable means may be provided for moving the scale 17. In this case, I have shown two solenoids 30 and 31 having cores.

32 and 33 connected to short radial arms 34 and 35 extending outward from opposite sides of the flange 27, for moving the scale to the left and right respectively. The terminals of the coil of solenoid 30 are connected respectively to contact 24 and to a binding post 36 and the terminals of the coil of solenoid 31 are connected to contact 25 and to a binding post- 37 respectively. The solenoid coils may be connected to any constant source of current such as a battery or in shunt to the conductors of the main circuit. At 38 is shown a fine spiral spring connected at one end to the spindle 12 of the-indicator and at its other end to a pin or other projection 39 of the flanged portion 27 of the scale. The purpose of the spring is to return the needle to its zero position, to oppose the torque of the coil and core of the actuating solenoid 20, and to :balance the pull of the scale-moving solenoids, as will be explained.

Bearing on the under side of the flange 27 is aleaf spring or brush 40 which is electrically connected to a binding post 41. The brush 40 serves a two-fold purpose, namely, to convey current to the indicator, which closes the circuit through one or the other of the solenoids 30 or 31 when the rearwardly extending armengages contact 2 1 or 25, and to put a drag on the scale so as to render the instrument deadbeat. If desired, the drag may be'dispensed with and the current .conveyed -to the indicator by some other means such as a fine flexible conductor.

Thepurpose and operation of the differout parts of the instrument will now be more fully explained, reference being had par--v ticularly to Fig. 3. Coil 21 is connected to the circuit conductors 42 and 4.3, which as I explained before may connect the coil in series or in shunt tothe load. The scaleactuating solenoids are in this case connected to a battery 44, one terminal of which is also connected to the brush 410. Normally the indicator and scale are in the position shown in Figs, 1 and 3, the re rwardly extending arm 18 of the needle being approximately midway between the contains '24 and 25 and the scale being at the eitt'rmne right through the coil of solenoid 30, the current 1 hand position. When there is a passage 0L.

value of the current in the coil is-smalL m near its pivotal center so that the movement of the solenoid core is very slight. The his.

us dtion of the solenoid core can be so adj that the pull, and movement is exactly portional to thevalue of the current. passing through the solenoid coil. i

The indicator may be very light so thatthe .friction in its bearings is almost negligible.

The solenoid is connected to the indicator hen the value of the current solenoid 21 exceeds a certain predetermined amount the indicator reaches its limiting position with the arm 18 in engagement with contact 24, and the circuit is ,completed being conveyed to the indicator through the brush i0, flange 27 of the scale and spiral spring 38. The core of solenoid 30 is now moved into the coil, moving the scale to the left and winding up the spring 38 until thet o pull of the spring barely exceeds the pull off, solenoid 20. The pull of the spring moves 5, the arm 18 of the indicator away from con-i tact 24, breaking the circuit through the coil of the solenoid 30. The scale now remainingin the same position, the pull of the solenoi 20 being insufiicient to overcome the friction of the scale on its bearing and the drag,if any, due to the brush 40, the indicator almost immediately assumes a stationary posim tion with the arm 18 out of engagement w th either contact, and the positions ofthe indicator and scale is an accurate indication of the current traversing the indicator motive device. As the current through the 0011 1 05 of solenoid 20 decreases, the pull of the solenoid decreases and the spiral spring}.

moves the indicator tothe left until the arm 18 engages contact 25, closing the, circuit through the coil of solenoid 31 to cause the l t scale to move to the right and unwind the spring 38. This movement continues until the pull of the spring is barely less than that of the solenoid 20, whereupon the arm 18 leaves the contact 25 and equilibrium is again immediately res ored. When the instrument is disconnected from the main cir c'uit the spiralspring pulls the indicator to the left until the arm '12 engages contact 25,

completing the circuitrthrough the coil of solenoid 31' which restores the scale to its normal position shown in the drawing, the indicator assuming a zero position with the arm 18 approximately midway between 0011* tacts 24 and 25.

The mechanical co'inections net U indicator and the solenoid 2G, a the scale and solenoids 30 and iii a ablv near the pivotal k enters if and scale so that comp arativr-ly will also be seen that the accuracy of the instrument is little affected by friction of the moving parts since the friction of the movable scale can notaft'ect the instrument.

It is evident that my invention can be embodied in a large number of forms or modifications, and I therefore do not wish to be confined to the specific details or arrangements of parts'here shown.

\Vhat I claim as new is 1. In an electrical measuring instrument, a movable indicator, a movable scale, and means for moving the scale only after the indicator has moved a predetermined distance.

2. In an electrical measuring instrument, an indicator and a movable scale, and means for automatically moving said scale only when theclcctrical condition to be measured exceeds a predetermined amount.

3. In an electrical measuring instrument, a movable pointer or indicator, a movable scale, and power operated means for moving said indicator and scale successively but in opposite directions upon a sufficiently large variation in the value of measured.

4. In an electrical measuring instrument, a movable indicator, a movable scale, means for moving one of said members only when the value to be measured is less than a certhe quantity to be tain predetermined amount, and means for moving the otherof said members when the value to be measured exceeds that amount.

I). In an electrical measuring instrument,-

a movable indicator, a movable scale, means for moving one only of said members for small variations in the value of the quantity to be measured, and both of said members for large variations in the value of the same uantity.

6. In an electrical measuring instrument, a movable pointer or indicator, a movable scale, means for moving only said indicator for small electrical measurements, and means for moving said scale for large measurements of the same quantity.

7. In an electrical measuring instrument, a n'iovable indicator, a movable scale, and a motive device for each of said movable arts, the motive device otpne of said parts eing controlled by the other.

8. In an electrical measuring instrument a mo 'able indicator, a movable Scale, an

means for causing a movement of the scale when the indicator reaches a certain position.

9. In an electrical measuring instrument, a movable indicator, a movable. scale, and means for causing a movement of the scale in one direction when the indicator has moved a predetermined distance in the opposite direction.

10. In an electrical measuring instrument, an indicator having a limited range of movement, a scale having a greater range of movement, and a motive device for each of said members, the motive device of the scale being controlled by the indicator.

11. In an electrical measuring instrument, an indicator, a motive device therefor, a movable scale, a motive device therefor, and means for closing the circuit through the motive device of the scale when the indicator has moved a predetermined distance.

12. In an electrical measuring instrument, an indicator, an electromagnetic motive device therefor, a movable scale, and an electromagnetic motive device therefor, said last named motive device having a circuit controlled by the movement of the indicator.

13. In an electric measuring instrument, a movable indicator, a movable scale cooperating with said indicator, a motive device for said indicator, said motive device being controlled by the electrical quantity to be measured, and a motive device for said scale, said last named motive device being controlled by said indicator.

14. In an electrical measuring instrument, a movable indicator, a movable scale, and a motive device for each of said movable parts,

one of said motive devices being 'controlled' 'by the position of the movable part operated by the other motive device, and said last mentioned motive device being controlled by the electrical quantity to be measured.

- 15. In an electrical measuring instrument,' an indicator having a limited range of movement, a movable'scale coiiperating therewith, and a motive device for each of said members, the motive device for the scale being operative only when the indicator is at one of itslimits of movement.

16.. In an electrical measuring instrument, an indicator having a limited range of movement, a movable scale cooperating therewith, a motive device for causing movements in opposite directions upon the rise and fall respectively in the value of the electrlcal quantity to be measured, and a motive device for movin said scale to continue n the same direction t e relative movement between said indicator and said scale when the indicator has reached the limit of its movement.

17. In an electric measuring instrument, a movable member having a imited range of movement, a second movable member, said two movable members coiiperating to form the indicator and scale of the measuring instrument, a motive device for said first movable member, said motive device'being controlled by variations in the electricalquan tity to be measured, and a motive device for said second movable member, said last named motive device being operative only when said first movable member is at one of its limits of movement.

18;' In an electrical measuring instrument, an indicator, a movable scale, and automatic means for'moving said scale only when variations in the electrical quantity to be measured exceed a predetermined amount.

19. In an electrical measuring instrument, a movable indicator, a movable scale, means for moving only one of said members when I variations in the value to be measured are essthan a predetermined amount, and means for moving the other of said members when such variations exceed that amount.

20. In an electrical measuring instrument, a movable indicator or pointer, a movable be measured, and means for moving said scale for large changes in the same quantity. In testimony whereof I affix my signature,

in the presenceof two witnesses.

4 HERMON l1. VAN VALKENBURG.

Witnesses ARTHUR F. Kwls, FRED J. Knvsnv.

scale, means for moving said indicator for small changes 1n the electrical condition to. 

